I use a nylon flat collar and

raisins mom

I use a nylon flat collar and sometimes a Sensible harness that hooks in the front.  A thought to try but unknown how well it will work is peanut butter on a wood spoon or spatula.  Put it in front of yer dogs nose and try to walk forward with your dog licking the peanut butter.  I only suggest the spatula so you wont hurt your back leaning over so much.  As they grow you can just hold a treat in your hand.  I use alot of treats when I walk Raisin.  I try to do all our training also when he is hungry so he pays even more attention to me because he wants that food.  Good luck to you and your pups!